Used as an intermediate in the synthesis of dyes, pharmaceuticals, and agrochemicals. Its aldehyde group allows for easy functionalization, making it valuable in organic synthesis, particularly in the preparation of sulfonated aromatic compounds. Commonly employed in the production of fluorescent whitening agents and optical brighteners for textiles and paper. Also utilized in the development of specialty polymers and as a building block in the creation of complex sulfonic acid derivatives for catalysis and material science applications.